Detent release mechanism



April 4, 1961 N. CZAJKOWSKI DETENT RELEASE MECHANISM Filed Aug. 9, 1955 ATTOR EYS DETENT RELEASE MECHANISM Norman Czajkowski, Chevy Chase, Md., assignor to the United States of America as represented by the Secretary of the Navy I Filed Aug. 9, 1955, Ser. No. 527,426 Claims. (Cl. 102-79) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to a fuze and more particularly to a new and improved safety device for a fuze.

Moreover, the invention provides a centrifugally actuated safety device for use in a fuzed spin ordnance missile to prevent premature arming of the fuze during handling, transportation and as the missile is fired from a gun. Furthermore, the device of the present invention provides a novel fluid filled flexible element having a locking detent carried thereby in locking engagement with the arming rotor of the fuze for maintaining the arming rotor thereof in a safe condition until themissile hasbeen fired from a gun or launched from a launching rack, as the a case may be, and adapted to release the arming rotor venting premature release and movement of the arming rotor to an armed position.

Another object of the invention is to provide a new and improved safety device for maintaining the armingrotor of a fuzed ordnance missile in a safe condition as the missile is fired from a gun or the like and which operates to release the arming rotor as the missile is rotated along its trajectory.

A further object of the invention is to provide a safety device for normally locking an arming rotor of an ordnance missile wherein means are provided for controlling the rate of flow of mercury from one chamber to another chamber in response to the spin of missile thereby to release the arming rotor for rotation to an armed position.

A still further object of the invention is to provide a new and improved centrifugally actuated safety device suitable for use with a continuously rotating member such, for example, as a fuzed projectile for delaying movement of the arming rotor of the fuze from an initial safe position to an armed position for a predetermined period of time after the projectile has been fired from a gun.

Other objects and many of the attendant advantages of this invention will be readily appreciated as 'the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. l is a plan view of a fuze arming rotor and casing illustrating the safety device of the present invention in locking engagement with the arming rotor and the rotor in a safe condition in accord with a preferred embodiment of the invention;

Fig. 2 is a view similar to Fig. 1 with the safety device in a released position and the arming rotor in an armed condition; and

Fig. 3 is a fragmentary sectional View illustrating the such, for example, as stainless steel or the like and having a locking detent 9 carried thereby and secured thereto as by welding the parts together as at 8. The safety device also includes a sump or receptacle 12 and a rigid delay element 13. The delay element is disposed between the bellows and sump 12, the sump having a flange 14 formed thereon in abutting engagement with one surface of the element 13, the annular member 13 being disposed in abutting engagement with the flange 15 and having an annular nipple formed thereon and secured to the bellows in any suitable manner as at 16 such, for example, as by welding the parts together. The aforesaid flanges 14 and 15 and delay element 13 are welded together as at 17 to provide an annular sealed joint therebetween. By

the aforesaid arrangement a pair of chambers 18 and 19 v understood, however, that when the pressure of mercury against the porous element is sustained by centrifugal force as the projectile spins along its trajectory, the mercury will continue to flow from chamber 19 through the element 13 into the sump 12. When a sufficient quantity of mercury has been transferred from chamber 19 to the chamber 18 in member 12, the bellows is contracted and the detent 9 carried thereby is moved out of locking engagement with the arming rotor generally indicated by the numeral 21.

i The arming rotor may be a conventional arming rotor such, for example, as the type shown and described in the copending application of Calvin F. Brown et al., Serial No. 299,324, filed July 16, 1952, titled Detonating Means for a Fuze. The rotor comprises a disc 22 pivotally mounted as at 23 to the rotor casing 24 and disposed with a recess 30 formed therein, the rotor being provided with a detonator 25 adapted to be brought into registration with a lead-in charge 26 arranged within the casing 24 and anelectroresponsive primer 27 when the rotor has been released and actuated from an initial safe position to an armed position as shown on Fig. 3. It will be noted in Fig. 1 that the arming rotor is locked in an initial safe position by the detent 9 carried by the bellows 11 and normally disposed within a complementary arcuate recess 28 formed in the rotor 22 by reason of the expanded condition of the bellows 11. It will be understood that when the pressure of mercury against the porous disc 13 is sustained by centrifugal force as the missile spins along its trajectory, the mercury will continue to flow from chamber 19 through disc 13 into chamber 18. When a sufficient quantity of mercury has been transferred from chamber 19 into chamber 18, the bellows will contract sufficiently to cause the detent 9 to be moved out of locking engagement with recess 28. When this occurs the rotor is released and rotated from the initial position to an armed position, Fig. 2.

When the rotor is moved to the armed position it will Patented Apr. 4, 1961 3 be noted, Fig. 3, that the detonator 25 is brought into registration with both the lead-in charge 26 and the electroresponsive primer 27 and further rotation of the rotor is prevented by the stop pin 31 carried by the rotor casing, Figs. 1 and 2.

By the aforesaid sintered disc arrangement it will be understood that the mercury will not flow therethrough in response to sudden and severe shocks and thus the detent will be maintained in locking engagement with the arming rotator and will release the arming rotor only when the pressure of mercury against the porous disc 13 is sustained by centrifugal force and sufficient mercury has passed therethrough to permit the bellows to contract a predetermined amount. Moreover, the arming rotor is adapted to be released and rotated to an armed position a predetermined period of time after the missile has been fired from a gun or the like such, for example, as one half second, the time interval being controlled by the rate of flow of the mercury through the aforesaid delay disc 13.

Briefly stated in summary, it will be apparent that a new and improved delay device has been devised for use in a fuzed projectile which operates to release the arming rotor thereof as the projectile spins along its trajectory and which will withstand repeated shocks of momentary duration without being actuated to a release position.

Obviously many modifications and variationsof the present invention are possible in the light of the above teachings. .It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a centrifugally actuated safety device for a spin projectile, in combination, a support, a normally locked arming rotor rotatably supported within said support, a mercury filled collapsible bellows disposed within said support and having a protuberance formed thereon in locking engagement with said rotor, and sintered means connected to the bellows for initially sealing the mercury therein and for passing the mercury only by centrifugal force under high sustained pressure from said bellows in an amount sutficient to allow contraction of the bellows thereby releasably disengaging said protuberance from said rotor when a predetermined period of time has elapsed after the projectile has been fired from a gun.

2. In a centrifugally actuated safety device for a spin projectile, in combination, a support, a normally locked arming rotor rotatably supported within said support,a mercury filled contractible bellows, a porous element on said bellows for initially sealing the mercury therein and for passing the mercury by centrifugal force under high sustained pressure from said bellows in an amount sufficient to allow contraction of the bellows when a predetermined period of time has elapsed after the projectile has been fired from a gun, and a detent on said bellows in locking engagement with said rotor for releasing the rotor as the bellows is contracted.

3. In a centrifugally actuated safety device for a spin projectile, in combination, a support, a hermetically sealed contractible bellows arranged in said support, a quantity of mercury disposed within and completely filling said' bellows, a sump carried by said support adjacent the bellows, a sintered porous disc disposed between said bellows and sump for initially sealing the mercury within the bellows and for forming a pair of chambers, said mercury being adapted to pass through said disc from one of the chambers to the other chamber in a sufiicient quantity to cause contraction of the bellow when the pressure of the mercury against said porous disc is sustained for a predetermined period of time by centrifugal force, a normally locked arming rotor rotatably supported within said support for movement from an initial safe position to an armed position when released, and a detent on said bellows in locking engagement with said rotor for locking the rotor in said initial safe position until said bellows is contracted.

4. In a locking device of the character disclosed comprising a sealed contractible bellows and a sump, a quantity of mercury disposed within and filling said bellows, a porous disc disposed between said bellows and sump for initially sealing the mercury within the bellows and for passing said mercury by centrifugal force from said bellows to said sump under high sustained pressure sufficient to cause contraction of said bellows when a predetermined period of time has elapsed, a locking detent carried by said bellows and controlled thereby, and an arming rotor normally locked by said detent.

5. A locking device of the character described comprising a normally expanded bellows, a quantity of mercury disposed within said bellows, a sump having a chamber therein disposed in closely spaced adjacency to said bellows, a rigid porous element disposed between said bellows and sump for initially sealing the mercury within the bellows and for passing said mercury by centrifugal force from said bellows to said chamber under high sustained pressure sufficient to cause contraction of said bellows when a predetermined period of time has elapsed, and a locking detent carried by said bellows and controlled thereby.

References Cited in the file of this patent UNITED STATES PATENTS 2,414,836 Rickmeyer Jan. 28, 1947 2,537,855 Porter Jan. 9, 1951 2,651,993 Berzof Sept. 15, 1953 

